Process of treating lead or lead alloys



Patented Apr. 26, loss 2 115 300 UNITED STATES. PATENT OFFICE William Thomas Butcher, 1110111, England, as- 1 sirnor to Goodlass Wall & Lead Industries Limited, London, England No Drawing. Application July 22, 1937, Serial No. 155,122. In Great Britain August 8, 1936 12 Claims. (CI. 75-48) This invention provides a general method of than one flux addition and this is specially so introducing a metal A into a bath of molten lead where preferential removal of a certain metal containing a metal B, which consists in treating from the bath is aimed at. the bath with a flux containing a lead halide and I a sulphide of the metal A, whereby an interac- 5 tion takes place resulting in the replacement of 1,040 P s Of a lead alloy fln a metal 3 1n t h th by t metal A, and t magnesium were stirred with 100 parts of lead tr ti in th flux 1 t form of sulphide, chloride and 25 parts of lead sulphide for fifteen This method can be employed for refining minutes nd h ma nesium in the alloy was lead alloys, by extractlon'therefrom of the metal te y rep ced by e d from the lead s B and its replacementby lead, in which case the phide- Similar results were Obtained using 11thfiux used will contain a lead halide and lead suli m, sodium, potassium, calci m. a mini m, pmd It can l b employed for introducing strontium and zinc as the metal B in the lead.

- int molten e d an alloying ingredient, in which Using lead fluoride instead of lead chloride with 5 case the bath consists f lead and h flux of lead sulphide similar results were obtained ex- 15 mixture of a lead halide and a sulphide of the cept that in the case of tin 64% was removed. metal to be alloyed with the lead. Further the H substitution in a lead alloy of one alloying constituent by another can be eifected. Thus if a 5 Parts bismuth sulphide and 50 parts of 0 lead alloy containing copper is treated with a lead fluoride were added to 1000 parts of molten lead hehde flux containing antimony sulphide, lead, and stirring continued for l5 minutes, when antimony will enter the bath and copper be exit was fmmd that 98% of the blsmuth W fl t t 1 t flux 1n the form of copper sulphide. replaced lead in the bath. .Uslng lead chloride in- In th m t not only o antimony replace stead of lead fluoride in the flux, 93% of the biscopper in the bath but a certain amount of lead mum was found in the bath- 25 is replaced as well. In all cases the method has m the a an t fivelydlflw figfi gfig gj g g fifgfgi fi gf a 1000 parts of lead containing 0.1% nickel were With certain metals the process is irreversible. treated with 50 Parts 9 ad fluoride and 25 parts 40 Thus arsenic antimony Silver tenurmm and lead sulphide and stirred for 20 minutes, after bismuth can be caused to replace lead or other which 12% 9 the contaltled mckel was f metals in the bath by incorporating them in the Using antimony sulphide In place of lead sulphlde flux in the form of sulphides but they cannot be the removed nickel was 48% of the total In a removed from the bath bytreatmg with sulphides case where the flux consisted of lead chloride and v of other metals once they are alloyed therein. lead 50% of the nickel. remOVed' Again lithium sodium, magnesium, aluminium This reaction, unlike those given in the prepotassium calcium, zinc, strontium and tin can ceding examples, is a reversible one. For examall be extracted from the bath by treatment with me by treating mflmn lead (1000 parts) with a a lead halide flux containing. lead sulphide, but flux consisting of lead fluoride (50 parts) and l they cannot be introduced into the bath by innickel sulphide (5 23% of the nickel pres corporation of a sulphide 01' any of these metals ent m the flux became alloyed with the lead' in the flux. IV w of as either the meta! A or the metal B were treated with parts of lead chloride and It has been found that pure sulphides need not 10 parts of lead sulphide for 15 minutes and the necessarily be employed but sulphide ores and whole of the strontium was removed from the residues can be used, metal v Some examples of how the invention can be so carried into eflect will now be 'givenz-l'n each of 1000 parts of lead containing 0.44% cadmium 5 the examples quoted below the lead alloy to be were stirred for 15 minutes with 50 parts of lead treated is melted in a kettle and heated to about chloride and 25 parts of lead sulphide after 550 C. The lead halide with the whole or a porwhich it was found that the whole of the cadtion of the sulphide of the metal A is then added mium was removed from the metal.

and the whole forms a fluid layer on the surface These reactions are likewise reversible. For 55 of the metal. Mixing is then commenced and is example, using a flux consisting of 5 parts of eflected by the, usual means until the reaction is cadmium sulphide and 50 parts of lead fluoride to finished, the balance, if any, of the metallic sultreat 1000 parts-of molten lead, it was found that phide being added meanwhile. 10% of the cadmium became alloyed with the In some cases it is preferable to make more lead.

- between the metal B and the said any one of the metals lithium,

As explained above, arsenic and antimony can be introduced into but not extracted from the bath by the method according to the invention.

Thus using lead fluoride as the flux, 1000 parts of molten lead were stirred for 15 minutes with parts of lead fluoride and 50 parts of antimony sulphide. It was found that 50% of the antimony replaced lead in the bath.

A similar experiment, in which 1000 parts of molten lead were stirred for 15 minutes with 50 parts of lead fluoride and 10 parts of arsenic sulphide resulted in 60% of the arsenic replacing lead in the bath. on repetition using lead chloride as the flux 62% of the arsenic was found to replace lead in the bath.

VII

The following is an example of the extraction of copper from lead alloys.

1000 parts of lead containing 0.04% copper were treated with parts of lead chloride and '70 parts of lead sulphide. After treatment the metal analyzed 0.0ll5% copper.

VIII

The following is an example of the extraction of selenium from lead alloys. On treating 1000 parts 0.033% selenium with 100 parts of lead chloride and 25 parts of lead sulphide and stirring for 20 minutes, 66% of the contained selenium was removed.

The following are examples of the alloying of silver, tellurium and bismuth with lead.

In each case 5 parts of sulphide of the metal mixed with 50 parts of 30% replaced lead in for tellurium and bismuth were respectively.

invention and desire to the steps of reacting upon a bath containing molten lead with a flux, consisting of a mixture of a'lead halide and a sulphide of a metal A having a less afllnity-for sulphur than a metal B present in the bath, thereby eil'ecting interaction sulphide and replacement thereof in the bath by the metal A, and removing the metal B by separating the flux from the bath.

2. A process the sulphide employed ore or residue.

3. A process for alloying with lead one of the metals arsenic, antimony, silver, tellurium, bismuth, which comprises the steps of treating a bath of molten lead with aflux, consisting of a mixture of a lead halide and a sulphide of one of the metals aioresaid, thereby replacing lead in the bath by the metallic constituent of the sulphide and removing the lead sulphide so formed by separating the flux from the alloy.

.4. A process according to claim 3, in which the sulphide employed in the flux is anvoxide ore or residue.

5. A process for according toclaim l, in which removing from a lead alloy sodiummagnesiformed by separating in the flux is a sulphide anesoo um, aluminium, potassium, calcium, zinc, strontium. tin, which comprises the steps of treating a bath of the molten alloy with a flux, consisting of a mixture of a lead halide and lead sulphide, thereby converting the metal to be removed into a sulphide and replacing it in the bath by lead and removing the metallic sulphide so formed by separating the flux from the bath.

6. A process according to claim 5, in which the sulphide employed in the flux is a sulphide ore or residue.

7. A process of treating lead, which comprises the steps of reacting upon a bath containing molten lead with a flux, consisting of a mixture of lead chloride and a sulphide of a metal A having a less amnity for sulphur than a metal B" present in the bath, thereby effecting interaction between the metal 5 and the said sulphide and replacement thereof in the bath by the metal A, and removing the metal B by separating the flux from the ba,

8. A process of treating lead, which comprises the steps of reacting upon a bath containing molten lead with a flux, consisting of a mixture of lead fluoride and a sulphide of a metal A having a less afllnity for sulphur than a metal B present in the bath, thereby eilecting interaction between the metal B and the said sulphide and replacement thereof in the bath by the metal A,

and removing the metal B by separating the flux from the bath.

9. A process for alloying with lead one of the metals arsenic, antimony, silver, tellurium, bismuth, which comprises the steps of treating a bath of molten lead with a flux, consisting of a mixture of lead chloride and a sulphide of one of the metals aforesaid, thereby replacing lead in the bath by the metallic constituent of the suiphide and removing the lead sulphide so formed by separating the flux from the alloy.

10. A process for alloying with lead one oi the metals arsenic, antimony, silver, tellurium, bismuth, whichcomprises the steps of treating a bath of molten lead with a flux, consisting of a mixture oi lead fluoride and a sulphide of one of the metals aforesaid, thereby replacing lead in the bath by the metallic. constituent of the sulphide and removing the lead sulphide so the flux from the alloy.

11. A process for removing from a lead alloy any one of the metals lithium, sodium, magnesium, aluminium, potassium, calcium, zinc, strontium, tin, which comprises the steps of treating a bath of the molten alloy with a flux, consisting of a mixture of lead chloride and lead sulphide, thereby converting the metal to be removed into a sulphide and replacing it in the bath by lead and removing the metallic sulphide so formed by separating the flux from the bath.

12. A process for removing from a lead alloy any one of the metals lithium, sodium, magnesium, aluminium, potassium, calcium, zinc, strontium, tin, which comprises the steps of treating a bath of the molten alloy with a flux, consisting of a mixture of lead fluoride and lead sulphide, thereby converting the metal to be removed into a sulphide and replacing it in the bath by lead and removing the metallic sulphide so formed by separating the flux from the bath.

wmusu THOMAS Bu'rcnna. 

